Perceiving Object Rotations — Effects of Egocentric Perspective and Observer Orientation

Abstract

Indicating the orientation of the axis of rotation of a rotating object is a fundamental part of an operator's ability to understand the motion of the object. Prior research has shown that this ability depends heavily on the orientation of the rotational axis with respect to the observer, the environment and the object. The present study is the first to distinguish between the involvement of egocentric and environment-centered spatial reference systems in rotation perception. Observers indicated the orientation of the axis of rotation for visually displayed motion while sitting upright or being tilted sideways or backwards. Accuracy and response time were recorded. The results showed that egocentric and environment-centered reference systems appear to play differential roles in the ability to accurately indicate the axis of rotation depending on the orientation of the observer. Theoretical and practical implications are discussed.